Line space feed mechanisms for power operated typewriters and the like



A ril 26, 1966 K. G. JONSSON LINE SPACE FEED MECHANISMS FOR POWER OPERATED TYPEWRITERS AND THE LIKE Filed NOV. 20, 1964 INVEN'IOR. KARL GUNNAR JONSSON BY v ATTORNEYS I the like.

United States Patent 3,247,943 liJllNE SPACE FEED MECHANISMS FOR POWER OPERATED TYPEWRKTERS AND THE LIKE Karl Gunnar .ldnsson, Karishamn, Sweden, assignor to Facit-li-lalda Aktiebolag, Svangsta, Sweden, a joint- The present invention relates to power-operated typewriters and like machines and particularly concerns a line space feed mechanism enabling line space feed movements to be carried out in every position of the platen carriage, notwithstanding if the latter is stationary, or not.

It is an object of the invention to provide line space feed mechanism the operational forces ofwhich become localized solely to the platen carriage, whereby the line spacing movement will become smooth and sure, and the carriage return movement will be shock-free.

It is another object to provide mechanism which has a soft and silent line space feed functioning. It is a further object to provide light-weight line space feed mechanism which will make for a swift-moving and silent carriage by reducing the carriage acceleration and retardation forces.

With these and other objects in view a preferred embodiment of the invention will be described with reference to the annexed drawing which illustrates by a perspective view a line space feed device according to the invention with its driving mechanism.

A ratchet wheel 1 is adapted in a manner known per se to be locked relative to a typewriter platen 2 rotatably journalled on a shaft 3 in the carriage frame (not illustrated) of the typewriter. At the same end of the platen 2 as the ratchet wheel 1 a line feed selecting member 4 is journalled by means of a bush on shaft 3. The feed selecting member 4 is sector-shaped and provided with an arc-shaped portion 4a covering part of the ratchet wheel circumference and formed at one end with a graduated scale 4b corresponding to different line feeds and manually operable. The feed selecting member 4 is adapted to be retained in a set position by a latch mechanism (not illustrated), and to control the engagement between the ratchet wheel 1 and a line space feed pawl 5. This pawl is pivoted on a feed lever 6 and is urged by a spring (not illustrated) to engage in the initial position of the feed lever 6 the arc-shaped portion of the feed selecting member 4. The feed lever 6 is journalled for angular movement on shaft 3 by means of a bush, and will perform a reciprocating movement during line feed.

Each time line feed takes place, the same amount of movement is imparted to feed lever 6, the latter or the line feed pawl 5 moving to abut a stop member illustrated by chain lines. The selecting member 4 commands by its setting the number of ratchet wheel teeth by which feed is effected, and matches the movement to make a latch roller later to be described always engage a gap between the ratchet wheel teeth.

The angular movements of the arm 6 are actuated by means of a cord 10, one end of which is connected to the outer, free end of feed lever 6, and the other end of which is secured to the carriage frame by a screw member 11 or (By the expression cord is implied any flexible member of a suitable strength and shape.) When the cord is tautened, the feed lever 6 is moved downwards. The feed pawl 5 will then slide off the arc-shaped portion of the line feed selecting member 4 and engage the ratchet wheel 1 to which a fractional rotation is imparted which corresponds to the line feed determined by selecting member 4, until the stop member illustrated by chain lines will arrest this motion.

3,247,943 Patented Apr. 26, 1966 The angular movements of the feed lever 6 will become synchronized with opposed angular movements of a latch lever 8. This lever 8 is by a rigidly attached stud 8a journalled in a hub (not illustrated) in the carriage frame and carries rotatably at one end a roller 8b which is urged by a compression spring 9 abutting the carriage frame to engage the ratchet wheel 1 whereby the platen 2 is secured circumferentially.

At the opposite end of the latch lever 8 a pulley 12 running in ball bearings (not illustrated) is mounted by means of a screw member 13 and a washer 14. The cord 10 is guided by the pulley 12 and will, upon angular movement of feed lever 6, impart to latch lever 8 an opposed angular movement, the latching action of the roller 811 on the ratchet wheel 1 and the platen 2 being temporarily suspended. When the original relative length of the cord 10 is resumed, the feed lever 6 is moved back to initial position by a tension spring 7 connected to the lever by one end and to the carriage frame by the other. The latch lever 8 is returned to its latching engagement with the ratchet wheel 1 by the compression spring 9.

The latch lever '8 may also, in a manner known per se, be disengaged from the ratchet wheel 1 by manually actuating a release lever 15 having a pivot 15a journalled in the carriage frame. A stud 15b attached to lever 15 is then brought outof engagement with a recess formed in the latch lever 8 imparting to the latter an angular movement such as to disengage the roller 8b from ratchet wheel 1.

The cord 10 is guided alternately over and under three pulleys 16, 17, 18. These pulleys all run in ball bearings. The pulleys 16 and 18 are supported by means of a screw member 20 and washer 21 by a bracket 19 secured to the machine frame, whereas the pulley 17 is supported by the outer end portion of a lever 22 adapted to be moved upwards and downwards and to control the relative length of cord upon its movement. The lever 22 is made up of two halves assembled to a unit by means of three studs 22a and adapted to turn on a pivot 23 secured to the machine frame. The outermost stud 22a supports the pulley 17, the middle one affords a connection for a t nsion spring 24, the opposite end of which is connected to bracket 19, and the innermost stud penetrates through a link member 25. This link member 25 is loosely, journalled on the pivot 23, and is provided at its bottom end with a stud 25a, by whichthe link member will be connected to control members actuated by the operator, and which may be of any suitable, known kind.

On pivotal movement of link member '25 as indicated by an arrow, the cord 10 is shortened relatively, and a line feed operation is actuated. The spring 24 returns the lever 22 and link member 25 to their initial positions after accomplished line feed.

The cord may be connected to the end of latch lever 8 and be guided over a pulley journalled at the end of the line space feed lever 6, instead. Such an arrangement will operate in a similar manner to the one described and illustrated.

What I claim is:

1. In a power operated office machine comprising platen means, a ratchet wheel, pawl means cooperative with said ratchet wheel for imparting line space feed movements to said platen means, a line space feed lever adapted to actuate said pawl means, and a latch lever adapted to retain said platen means circumferentially when engaging said ratchet wheel, the provision of cord means connecting the end of one of said levers over guide means disposed at the end of the other of said levers to actuating means adapted to tighten said cord means thereby to disengage said latch lever from said ratchet wheel and impart line space feed movements to said platen by means of said line space feed lever.

, 2. In a power operated typewriter comprising a platen, a ratchet wheel, pawl means engageable with said ratchet wheel for imparting line space feed movements to said platen, a line space feed lever connected to said pawl means to actuate the latter, and a latch lever engaging by spring action said ratchet wheel to retain said platen circumferentially in any one of a number of angular positions, the provision of cord means, said cord means connected by one end to the end of one of said levers, a guide pulley rotatably journalled to the end of the other of said levers, said cord means connected by its other end to stationary structure, and tightening means adapted to impart a pulling action to said cord means, thereby to actuate said levers.

3. A power operated typewriter as claimed in claim 2, wherein said tightening means comprise a series of pulleys disposed diametrically opposite said cord means, at least one of said pulleys being adapted to be moved transversally to tighten said cord means.

4. A line space feed mechanism for power operated typewriters comprising a ratchet wheel for imparting line space feed movements to a typewriter platen, pawl means adapted to engage said ratchet wheel, a sector-shaped line space feed selector member having an arc-shaped portion masking ofi said ratchet wheel circumference to control the engagement between said pawl means and said ratchet wheel, a line space feed lever pivotally supporting said pawl means, a latch lever having a rotatably supported roller at the end thereof for engagement with said ratchet wheel, said levers adapted to disengage said latch lever roller and to fractionally rotate said ratchet wheel, respectively, upon having their free ends moved toward each other, a cord connecting the free end of one of said levers to stationary structure over a guide pulley supported by the free end of the other lever, two pulleys disposed at one side of said cord and a third pulley at the opposite side between said two pulleys, said third pulley being adapted to be moved in between said two pulleys to tighten said cord, thereby to actuate said levers for etfecting line space feed movements.

5. A line space feed mechanism for power operated typewriters as claimed in claim 4, wherein said third pulley is rotatably supported by one end of a spring-loaded two-armed lever, the other end of said lever connected to linkage adapted to be actuated by the operator.

References Cited by the Examiner UNITED STATES PATENTS 1,138,993 5/1915 Steele 197122 X 1,141,558 6/1915 Kurowski 197--122 X 1,345,093 6/1920 Kurowski 197ll4 2,279,141 4/1942 Kittel 197-66 ROBERT E. PULFR-EY, Primary Examiner.

ERNEST R. WRIGHT, Assistant Examiner. 

1. IN A POWER OPERATED OFFICE MACHINE COMPRISING PLATEN MEANS, A RATCHET WHEEL, PAWL MEANS COOPERATIVE WITH SAID RATCHET WHEEL FOR IMPARTING LINE SPACE FEED MOVEMENTS TO SAID PLATEN MEANS, A LINE SPACE FEED LEVER ADAPTED TO ACTUATE SAID PAWL MEANS, AND A LATCH LEVER ADAPTED TO RETAIN SAID PLATEN MEANS CIRCUMFERENTIALLY WHEN ENGAGING SAID RATCHET WHEEL, THE PROVISION OF CORDS MEANS CONNECTING THE ENDS OF ONE OF SAID LEVERS OVER GUIDE MEANS DISPOSED AT THE END OF THE OTHER OF SAID LEVERS TO ACTUATING MEAN ADAPTED TO TIGHTEN SAID CORD MEANS THEREBY TO DISENGAGE SAID LATCH LEVER FROM SAID RATCHET WHEEL AND IMPART LINE SPACE FEED MOVEMENTS TO SAID PLATEN BY MEANS OF SAID LINE SPACE FEED LEVER. 